- The original Squid Log Analyzer I wrote wasn't what I really wanted. I had promised myself that I would get back to it to do a better job, but of course I forgot about that until someone asked me to provide some changes. I then looked at the code again and said no, this won't do.

- Unix and Linux machines have been able to provide Network Neighborhood style file and print services for some time now, but I constantly see confusion and problems due to misunderstanding of how these things work.

- Basic OS concepts. The CPU (Central Processing Unit) is the heart of any computer, but the operating system is the brain. Unfortunately, understanding exactly how these things really work can be difficult, because it's fairly hard to "play" with the operating system that you are actually using. You can do quite a bit with sophisticated debuggers, but eventually you run into confusion and difficulty. And, as you try more complex tasks, you run the risk of interfering with the real machine's operating system. Finally, modern CPU's are very complex, and that complexity can make it more difficult to understand basic concepts.